fn main() {
    // assert_eq!(10_i8.checked_add(20), Some(30));
    // assert_eq!(10_i8.checked_mul(20), Some(200));
    // assert_eq!(100_u16.wrapping_mul(200),20000);
    let bits = vec!["veni", "vidi", "vici"];
    println!("{}",bits.concat());
    println!("{}",bits.join(","));
}
